openwrt/target/linux/generic/pending-5.15/732-14-net-ethernet-mtk_eth_soc-drop-generic-vlan-rx-offloa.patch

From: Felix Fietkau <nbd@nbd.name>
Date: Sun, 20 Nov 2022 23:01:00 +0100
Subject: [PATCH] net: ethernet: mtk_eth_soc: drop generic vlan rx offload,
 only use DSA untagging

Through testing I found out that hardware vlan rx offload support seems to
have some hardware issues. At least when using multiple MACs and when receiving
tagged packets on the secondary MAC, the hardware can sometimes start to emit
wrong tags on the first MAC as well.

In order to avoid such issues, drop the feature configuration and use the
offload feature only for DSA hardware untagging on MT7621/MT7622 devices which
only use one MAC.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2001,29 +2001,16 @@ static int mtk_poll_rx(struct napi_struc
 		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
 			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
 
-		if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX) {
-			if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
-				if (trxd.rxd3 & RX_DMA_VTAG_V2)
-					__vlan_hwaccel_put_tag(skb,
-						htons(RX_DMA_VPID(trxd.rxd4)),
-						RX_DMA_VID(trxd.rxd4));
-			} else if (trxd.rxd2 & RX_DMA_VTAG) {
-				__vlan_hwaccel_put_tag(skb, htons(RX_DMA_VPID(trxd.rxd3)),
-						       RX_DMA_VID(trxd.rxd3));
-			}
-		}
-
 		/* When using VLAN untagging in combination with DSA, the
 		 * hardware treats the MTK special tag as a VLAN and untags it.
 		 */
-		if (skb_vlan_tag_present(skb) && netdev_uses_dsa(netdev)) {
-			unsigned int port = ntohs(skb->vlan_proto) & GENMASK(2, 0);
+		if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2) &&
+		    (trxd.rxd2 & RX_DMA_VTAG) && netdev_uses_dsa(netdev)) {
+			unsigned int port = RX_DMA_VPID(trxd.rxd3) & GENMASK(2, 0);
 
 			if (port < ARRAY_SIZE(eth->dsa_meta) &&
 			    eth->dsa_meta[port])
 				skb_dst_set_noref(skb, &eth->dsa_meta[port]->dst);
-
-			__vlan_hwaccel_clear_tag(skb);
 		}
 
 		skb_record_rx_queue(skb, 0);
@@ -2840,29 +2827,11 @@ static netdev_features_t mtk_fix_feature
 
 static int mtk_set_features(struct net_device *dev, netdev_features_t features)
 {
-	struct mtk_mac *mac = netdev_priv(dev);
-	struct mtk_eth *eth = mac->hw;
 	netdev_features_t diff = dev->features ^ features;
-	int i;
 
 	if ((diff & NETIF_F_LRO) && !(features & NETIF_F_LRO))
 		mtk_hwlro_netdev_disable(dev);
 
-	/* Set RX VLAN offloading */
-	if (!(diff & NETIF_F_HW_VLAN_CTAG_RX))
-		return 0;
-
-	mtk_w32(eth, !!(features & NETIF_F_HW_VLAN_CTAG_RX),
-		MTK_CDMP_EG_CTRL);
-
-	/* sync features with other MAC */
-	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		if (!eth->netdev[i] || eth->netdev[i] == dev)
-			continue;
-		eth->netdev[i]->features &= ~NETIF_F_HW_VLAN_CTAG_RX;
-		eth->netdev[i]->features |= features & NETIF_F_HW_VLAN_CTAG_RX;
-	}
-
 	return 0;
 }
 
@@ -3176,30 +3145,6 @@ static int mtk_open(struct net_device *d
 	struct mtk_eth *eth = mac->hw;
 	int i, err;
 
-	if (mtk_uses_dsa(dev) && !eth->prog) {
-		for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) {
-			struct metadata_dst *md_dst = eth->dsa_meta[i];
-
-			if (md_dst)
-				continue;
-
-			md_dst = metadata_dst_alloc(0, METADATA_HW_PORT_MUX,
-						    GFP_KERNEL);
-			if (!md_dst)
-				return -ENOMEM;
-
-			md_dst->u.port_info.port_id = i;
-			eth->dsa_meta[i] = md_dst;
-		}
-	} else {
-		/* Hardware special tag parsing needs to be disabled if at least
-		 * one MAC does not use DSA.
-		 */
-		u32 val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
-		val &= ~MTK_CDMP_STAG_EN;
-		mtk_w32(eth, val, MTK_CDMP_IG_CTRL);
-	}
-
 	err = phylink_of_phy_connect(mac->phylink, mac->of_node, 0);
 	if (err) {
 		netdev_err(dev, "%s: could not attach PHY: %d\n", __func__,
@@ -3240,6 +3185,35 @@ static int mtk_open(struct net_device *d
 	phylink_start(mac->phylink);
 	netif_tx_start_all_queues(dev);
 
+	if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2))
+		return 0;
+
+	if (mtk_uses_dsa(dev) && !eth->prog) {
+		for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) {
+			struct metadata_dst *md_dst = eth->dsa_meta[i];
+
+			if (md_dst)
+				continue;
+
+			md_dst = metadata_dst_alloc(0, METADATA_HW_PORT_MUX,
+						    GFP_KERNEL);
+			if (!md_dst)
+				return -ENOMEM;
+
+			md_dst->u.port_info.port_id = i;
+			eth->dsa_meta[i] = md_dst;
+		}
+	} else {
+		/* Hardware special tag parsing needs to be disabled if at least
+		 * one MAC does not use DSA.
+		 */
+		u32 val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
+		val &= ~MTK_CDMP_STAG_EN;
+		mtk_w32(eth, val, MTK_CDMP_IG_CTRL);
+
+		mtk_w32(eth, 0, MTK_CDMP_EG_CTRL);
+	}
+
 	return 0;
 }
 
@@ -3724,10 +3698,9 @@ static int mtk_hw_init(struct mtk_eth *e
 	if (!MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
 		val = mtk_r32(eth, MTK_CDMP_IG_CTRL);
 		mtk_w32(eth, val | MTK_CDMP_STAG_EN, MTK_CDMP_IG_CTRL);
-	}
 
-	/* Enable RX VLan Offloading */
-	mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);
+		mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);
+	}
 
 	/* set interrupt delays based on current Net DIM sample */
 	mtk_dim_rx(&eth->rx_dim.work);
@@ -4365,7 +4338,7 @@ static int mtk_add_mac(struct mtk_eth *e
 		eth->netdev[id]->hw_features |= NETIF_F_LRO;
 
 	eth->netdev[id]->vlan_features = eth->soc->hw_features &
-		~(NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX);
+		~NETIF_F_HW_VLAN_CTAG_TX;
 	eth->netdev[id]->features |= eth->soc->hw_features;
 	eth->netdev[id]->ethtool_ops = &mtk_ethtool_ops;
 
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -48,7 +48,6 @@
 #define MTK_HW_FEATURES		(NETIF_F_IP_CSUM | \
 				 NETIF_F_RXCSUM | \
 				 NETIF_F_HW_VLAN_CTAG_TX | \
-				 NETIF_F_HW_VLAN_CTAG_RX | \
 				 NETIF_F_SG | NETIF_F_ALL_TSO | \
 				 NETIF_F_IPV6_CSUM |\
 				 NETIF_F_HW_TC)